Studies are planned of hemodynamics, metabolism, and respiratory function in man and in laboratory animals in shock. Data will be recorded at the bedside from selected patients with hemorrhage or who are in shock from a variety of causes, including hypovolemia, sepsis, cardiac disease, pulmonary embolism and others. Adjuncts to the therapy of shock in man are being evaluated. Of particular interest are the effects of controlled hypotension in selected cases of continuing hemorrhage, and the influence of changes in hematocrit on viscosity of blood and rates of bleeding. Hypotheses derived from observations in man will be tested in the experimental laboratory. Observations being made in the experimental laboratory include studies of the effects of hematocrit on viscosity, flow rates, and bleeding rates in vitro and in the experimental animals, hemodynamics of inflammation and shock, changes in purine metabolism in shock, and morphologic changes of the brain in severe hemorrhage.